(1) Field of the Invention
The invention relates to a sealing device for sealing a pressure measuring cell housing, to a pressure measuring cell device comprising such a sealing device, and to a pressure measuring device comprising such a pressure measuring cell device.
(2) Description of Related Art
Generally known from DE 100 64 811 A1 is a pressure measurement device comprising a housing, wherein a pressure measurement cell is inserted in the front section of the housing. The pressure measurement cell is inserted in the front of the housing by means of special clamping elements. Furthermore, the pressure measurement cell is connected toward the back to a circuit board, wherein the circuit board typically comprises evaluation electronics and is received inside the housing. In the case of a pressure measurement cell operating with the reference pressure, in addition a pressure compensating line is routed through the housing toward the back from the back of the pressure measuring cell.
Particularly in the case of a measuring device for hydrostatic fill level measurement using such integrated electronic circuits, the housing is filled at the back of the pressure measuring cell with a casting compound, such as a curable silicon compound. This serves the protection of the electrotechnical components on the one hand and the reduction of the inner air volume within the housing on the other hand.
It is also generally known to solder pressure measuring cell electronics in a metallic housing, in which a circuit board is received, in a sealing fashion, wherein the pressure compensation is enabled by means of a hose guided through the housing. Often, such measuring devices comprise capacitively evaluating pressure measurement cells.
Configurations of this type are disadvantageous particularly when using a casting material, if this material enters the direct vicinity of an electronics component of the pressure measuring cell, because the casting compound in a capacitive measuring system negatively impacts the temperature behavior, which is to say the short-term behavior, but also the long-term behavior.